How To: Airbleed vs Twin Needle Carb 

I discovered a major error in this video. At 3:20 I begin talking about a lean or rich mixture and what the RPM does. I mis-spoke. If at idle the RPM slowly increases and then the engine dies it is LEAN. If the idle RPM slowly decreases then the mixture is RICH. My apologies for this error.

And the master has spoken! Another great instructional video Dave. Thanks and keep them coming.

Thank you for the info on the air bleed screw

I'm learning alot. Just got a Enya 40 x. Cleaned and ready to fire

Dave thanks for the video. I have a Super Tiger G90 engine that is a real pain to get it right on running . Out of three G90's I have one that is not running right. I will have to try this. Thanks again.

Good video................I wish more people would view it.

Thanks buddy! My new predator 212 carb has this screw and no one has said how to adjust it.

Another excellent "How To" video!

Thanx...today started up a 4 cc OS max after 25 years.. It ran practically instantly.

Lol, I cought that right away...working on small engines taught me that. I am very much familure with air bleed systems. Working with this stuff is important. I had a snow blower that would surge reguardless of adjustment, turned out the air bleed jet was too small from the factory. All those engines surged like mad at idle but quit at high speed. After I got frustrated with trying to figure it out, I got on line and someone had already fugured it out. By drilling the air bleed jet out just one size up completely fixed the issue. I had just fixed a Craftsman riding mower twin engine with a chinese after market engine with the same issue. I was able to drill out the main jet to get it to run right. The owner had replaced it with an aftermarket carb from China. Yeah,great huh?

Do a follow up explaining mechanically how both systems only work when the barrel is closed to an idle setting. IOW, why not open up the primary NV or Carb a little?

I think I still have a problem with my OS max carb. The needle housing got unscrewed and I didn't really take note of how deep the nozzle was in the carb. I placed it as I thought it should be. What I noticed is that even with a lean mixture the carb sputters and also noticed the nozzle of your carb is in deeper. I think I need to test the engine with the fuel nozzle deeper in the carb cause this is makes an even bigger mess than it already is and it must use absurdly more fuel than necesary.

hi David I have a OS MAX 40 FP mounting in a airplane. When I got this engine it was a slightly frozen so I took my heat gun and heated it up then I ran a tank of 10% nitro thru it. Now in the airplane I have it I was having a hard time getting the high speed needle to lean out then all of sudden it came right up. so I flew around and it got better. Then i quit and came home I went back a couple days ago and it was running great with exception if I put the engine in idle it would cackle and surge then it would die so I opened up the air bleed a 1/8 of a turn and the engine would not start. I put it back to where I thought it was set and now I was able to the high speed needle to lean out. any suggestions would be very helpfull thanks Michael

hello friend, very good your teachings, i have a carburetor for the 65 LA engine and the cylinder is locked, do you know how to unlock? Thanks.